1. Field of the Invention
This invention relates to an improvement in a slurry hydroconversion process in which coal is hydroconverted to liquid products utilizing a chromium-containing catalyst prepared from catalyst precursor dispersed in a hydrocarbon.
2. Description of Information Disclosures
Slurry coal hydroconversion processes (i.e., coal liquefaction) utilizing a catalyst prepared in a hydrocarbonaceous oil from a thermally decomposable or oil soluble chromium compound catalyst precursor are known. See, for example, U.S. Pat. Nos. 4,077,867 and 4,369,106. The term "hydroconversion" with reference to coal is used herein to designate a catalytic conversion of coal to liquid hydrocarbonaceous product in the presence of hydrogen.
It has now been found that the activity of the chromium catalyst can be increased when the chromium catalyst is preformed in a hydrocarbonaceous medium at concentrations greater than 0.1 wt. % (1000 ppm) Cr, in the absence of coal. The preformed catalyst in the hydrocarbonaceous medium is added to the diluent in which the coal is dispersed.